In which case a body will have maximum weight? Water or in vacuum.

Answer

To determine in which case a body will have maximum weight, whether in water or in a vacuum, we can analyze the forces acting on the body in both scenarios.

### Step-by-Step Solution:

1. **Understanding Weight in Vacuum**:
- When a body is in a vacuum, there are no opposing forces acting on it. The only force acting on the body is its weight due to gravity.
- The weight of the body (W) can be calculated using the formula:
\[ W = mg \]
where \( m \) is the mass of the body and \( g \) is the acceleration due to gravity.

2. **Understanding Weight in Water**:
- When the same body is submerged in water, it experiences a buoyant force (F_b) due to the water.
- The buoyant force can be calculated using Archimedes' principle:
\[ F_b = \rho_w \cdot V \cdot g \]
where \( \rho_w \) is the density of water, \( V \) is the volume of the body (which is equal to the volume of water displaced), and \( g \) is the acceleration due to gravity.
- The apparent weight (W') of the body when submerged in water is given by:
\[ W' = W - F_b = mg - F_b \]
Substituting for the buoyant force:
\[ W' = mg - \rho_w \cdot V \cdot g \]

3. **Comparing Weights**:
- In vacuum, the weight is simply \( W = mg \).
- In water, the apparent weight is:
\[ W' = mg - \rho_w \cdot V \cdot g \]
- Since the buoyant force reduces the weight of the body when submerged in water, we can conclude:
\[ W' < W \]

4. **Conclusion**:
- Therefore, the body will have maximum weight in a vacuum because there are no opposing forces acting on it, while in water, the buoyant force reduces its apparent weight.

### Final Answer:
The body will have maximum weight in **VACUUM**.